JP5284902B2 - Latent heat recovery type water heater - Google Patents

Description

  The present invention relates to a latent heat recovery type water heater having a drain neutralization tank for neutralizing and draining strongly acidic drain water.

  Conventionally, in this type, drain water generated when the temperature of the exhaust gas drops below the dew point due to heat exchange between the exhaust gas after combustion and the latent heat exchanger is replaced by a neutralizer filled with a neutralizing agent. The product was neutralized and drained by circulating it.

JP 2001-272110 A

  By the way, in this conventional system, when the neutralization tank is clogged, the neutralization tank is filled with drain water and is filled with the drain water up to the exhaust path of the instrument, and the neutralization tank of the neutralization tank is the first place where abnormal combustion occurs. Clogging is detected, and this is also the case with water leakage from the heat exchanger, and there is a problem that clogging of the neutralization tank and water leakage from the heat exchanger cannot be accurately detected. Met.

In order to solve the above-mentioned problems, the present invention particularly has a configuration in which a main heat exchanger that recovers sensible heat from exhaust gas generated by combustion of a combustion burner and heats running water, and a heat exchanger that exchanges heat with the main heat exchanger. An auxiliary heat exchanger that supplies the main heat exchanger with flowing water heated and recovered from latent heat from exhaust gas, and the auxiliary heat exchanger that houses the exhaust gas inlet above the bottom and the outlet at the top. A heat exchange case, and a neutralization tank filled with a neutralizing agent for neutralizing and draining strongly acidic drain water generated in the auxiliary heat exchanger in communication with the bottom of the heat exchange case, and The heat exchange case and the main heat exchanger communicate with each other through a silencer part at the lower part of the main heat exchanger, and a bypass passage that communicates the lower part of the silencer part and the inlet of the heat exchange case , and the exhaust gas passes through the sun reenser part and the bypass. Make a U-turn in the passage and enter the heat exchange case In those manner, the bypass passage is provided with an exhaust thermistor for detecting the soot clogging of the main heat exchanger by sensing the rise in exhaust gas temperature, the exhaust thermistor clogging of the neutralization tank or the main The leakage of water in the heat exchanger and the auxiliary heat exchanger also detects a decrease in the detected temperature due to dripping of the leaked water, stops combustion, and notifies this.

  As described above, according to the present invention, the communication port before the neutralization tank is clogged or the neutralization tank itself is clogged, or water leakage occurs from the main heat exchanger or the auxiliary heat exchanger. Drops to the exhaust thermistor in the bypass passage or reaches this position, so that the detection temperature of the exhaust thermistor that detects clogging of the main heat exchanger is usually 20 to 70 ° C. due to abnormal exhaust gas temperature at 200 ° C. or higher. Therefore, it is possible to accurately detect clogging of the neutralization tank and water leakage of the main heat exchanger and auxiliary heat exchanger to stop combustion and notify this, so the communication port in front of the neutralization tank Stops combustion by detecting multiple abnormalities with one exhaust thermistor, without the need for a special sensor for clogging of the neutralization tank itself or water leakage of the main heat exchanger and auxiliary heat exchanger Or let you know about this, Umate is economical and efficiency is good and safe, are those that can be used with confidence for a long time.

The schematic block diagram of one Embodiment of this invention. Explanatory drawing of the heat exchange case. The block diagram of the principal part electric circuit.

Next, an embodiment of the present invention will be described with reference to the drawings.
1 is a main body of a water heater, and a combustion chamber 4 having a gun-type combustion burner 2 and a combustion fan 3 mounted downward at the upper end is provided inside, and the combustion chamber 4 further includes a combustion chamber 4. A main heat exchanger 5 for recovering sensible heat of exhaust gas is provided.

  Reference numeral 6 denotes a silencer part for silencing constituting the bottom of the combustion chamber 4, which communicates with the main heat exchanger 5 at the center, and an L-shaped bypass passage 7 is connected to the end of the silencer. Is connected to the inlet 9 of the upper heat exchange case 8, and the exhaust gas from the combustion chamber 4 is U-turned through the silencer 6 and the bypass passage 7, and the combustion fan passes from the upper outlet 10 through the heat exchange case 8. 3 is discharged with a blowing force of 3.

  In the heat exchange case 8, an auxiliary heat exchanger 14 configured by arranging a plurality of heat receiving pipes 13 made of a meandering stainless pipe between the forward header 11 and the return header 12 is housed. This auxiliary heat exchanger 14 heats the feed water by recovering latent heat in the exhaust gas, and supplies the heated water to the main heat exchanger 5.

  15 is a neutralization that collects drain water generated from the auxiliary heat exchanger 14 in communication with the heat exchange case 8 through an inflow pipe 17 that communicates with a communication port 16 formed at the bottom of the heat exchange case 8. In the tank, the inside is divided into two chambers by a partition plate 18, and a neutralizing agent 19 made of calcium oxide granules that neutralizes the strongly acidic drain water is filled in both chambers. The water is neutralized by the neutralizing agent 19 and drained from a drain pipe 20 provided at a substantially middle portion in the height direction.

  Reference numeral 21 denotes a hot water supply control circuit constituted by a microcomputer, which is connected to a remote controller 22 provided in the kitchen or the like, and communicates with the main heat exchanger 5 so that the hot water supply temperature becomes the hot water supply set temperature set by the remote controller 22. The amount of combustion of the combustion burner 2 is controlled in accordance with the detected temperature of the hot water supply thermistor 24 provided in the hot water supply pipe 23, and the hot water supply control circuit 21 detects flowing water by the flow sensor 25 also provided in the hot water supply pipe 23. By doing so, the combustion burner 2 starts combustion as the combustion fan 3 starts to be driven.

  An exhaust thermistor 26 protrudes from the side wall in the middle of the bypass passage 7 and is provided below the inlet 9 and detects the exhaust gas temperature after passing through the main heat exchanger 5. However, when the main heat exchanger 5 is clogged with soot, 260 ° C. or more is detected and the clogging of the main heat exchanger 5 is displayed on the display unit 27 of the remote controller 22 via the hot water supply control circuit 21. The exhaust thermistor 26 is connected to the communication port 16 and the inflow pipe 17 away from the neutralization tank 15, and the neutralization tank 15 and the drain pipe 20 have dust or the like. The drain water overflows into the bypass passage 7 from the inlet 9 on the bottom surface of the heat exchanger case 8 and drops into the exhaust thermistor 26. The exhaust thermistor 26 is rapidly cooled to detect 70 ° C. or less, thereby connecting the communication port. 16, inflow pipe 17 The hot water supply control circuit 21 judges whether the neutralization tank 15 and the drain pipe 20 are clogged with dust or the like, or whether the auxiliary heat exchanger 14 is in a water leak state. In addition to being in the out state, the notification is displayed on the display unit 27 of the remote controller 22 or by making an error sound.

The exhaust thermistor 26 detects that the silencer section 6 and the bypass passage 7 overflow with water due to water leakage from the main heat exchanger 5 and the exhaust thermistor 26 is submerged in water, so that the temperature is lowered to 20 ° C. to 70 ° C. In the same manner as described above, not only the combustion is stopped, but also all the operations are stopped and the lockout state is established, and an error sound is displayed on the display unit 27 of the remote controller 22. To inform you.
A water supply pipe 28 is connected to the auxiliary heat exchanger 14.

Next, the operation of this embodiment will be described.
When a hot water tap (not shown) at an appropriate location is opened and hot water supply is started, the flow sensor 25 detects the flow of the hot water and the combustion fan 3 is driven via the hot water control circuit 21 so that the combustion burner 2 Starts combustion, and the exhaust gas generated by this combustion makes a U-turn from the combustion chamber 4 through the silencer section 6 and the bypass passage 7 and flows into the heat exchange case 8. The heat exchange with the feed water flowing into the auxiliary heat exchanger 14 is exhausted from the outlet 10.

  The hot water whose temperature has risen in the auxiliary heat exchanger 14 flows into the main heat exchanger 5 where it is further heated by heat exchange with the exhaust gas generated by the combustion of the combustion burner 2 and discharged from the hot water tap as hot water. The combustion amount (thermal power) of the combustion burner 2 at this time is detected by the hot water supply thermistor 24 provided in the hot water supply pipe 23 exiting the main heat exchanger 5, and this temperature is determined by the user himself / herself. It is adjusted so as to reach a hot water supply set temperature set by the remote controller 22.

  Next, in the heat exchange case 8, the drain water generated by the latent heat recovery of the feed water and exhaust gas flowing through the auxiliary heat exchanger 14 is naturally transferred from the outer peripheral wall of the auxiliary heat exchanger 14 to the bottom of the heat exchange case 8. It is collected by dropping, flows into the neutralization tank 15 from the communication port 16 through the inflow pipe 17, and the drain water is neutralized by the neutralizing agent 19 filled in the neutralization tank 15 to reduce the PH. The water is drained from the drain pipe 20, and the drain water generated in the auxiliary heat exchanger 14 is sequentially processed to improve the heat exchange efficiency.

  Further, when the clogging of the main heat exchanger 5 is detected by the exhaust thermistor 26, the detected temperature of the exhaust thermistor 26 is read by the hot water supply control circuit 21 at all times, and the exhaust gas temperature flowing into the heat exchange case 8 becomes the exhaust thermistor 26. When the temperature is 260 ° C. or higher, the fact that the main heat exchanger 5 is clogged is indicated on the display unit 27 of the remote controller 22 connected to the output side via the hot water supply control circuit 21. May be displayed to notify the user, and at the same time, an error sound may be emitted from the remote controller 22.

  On the other hand, if the communication port 16 or the inflow pipe 17 located away from the neutralization tank 15 or the neutralization tank 15 itself or the drain pipe 20 near the neutralization tank 15 is clogged with dust or the like, Drain water overflows at the bottom, overflows into the bypass passage 7 from the inlet 9, drops into the exhaust thermistor 26, and the exhaust thermistor 26 is rapidly cooled to detect 70 ° C. or less, whereby the communication port 16 and the inlet pipe 17 are detected. The hot water supply control circuit 21 determines whether the neutralization tank 15 and the drain pipe 20 are clogged with dust or the like, or whether the auxiliary heat exchanger 14 is in a water leak state. In addition to being in a lockout state, the notification is displayed on the display unit 27 of the remote controller 22 or by making an error sound.

  Further, in the case where the main heat exchanger 5 leaks water, the exhaust thermistor 26 has a detection temperature lowered to 20 ° C. to 70 ° C. when the silencer section 6 and the bypass passage 7 overflow with water and the exhaust thermistor 26 is immersed in water. Therefore, as well as the above, through the hot water supply control circuit 21, not only the combustion is stopped, but also all the operations are stopped to be in the lockout state, and are displayed on the display unit 27 of the remote controller 22 or an error sound is generated. To inform.

  As a result, only the exhaust thermistor 26 detects clogging of the main heat exchanger 5 due to soot, as well as overflow detection and neutralization of drain water due to clogging of the communication port 16 and the inflow pipe 17 located away from the neutralization tank 15. Can detect leaks of drain water due to clogging of the neutralization tank 15 itself or the exhaust pipe 20 close to the tank 15, and can also detect water leakage of the main heat exchanger 5, and can easily detect a number of abnormalities with one sensor. In addition to reducing the number of parts, the structure can be simplified and the number of assembly steps can be reduced. There is no risk of cost reduction or malfunction, and the use of one sensor in the bypass passage 7 enables efficient use. Detection of clogging in the heat exchanger 5 prevents abnormal combustion, and clogging in a place away from the neutralization tank 15 or in the opposite direction is also accurately detected, and drain water overflow reliably prevents parts from being oxidized or damaged. , In which was to be able to use with confidence over a long period of time.

2 Combustion Burner 3 Combustion Fan 5 Main Heat Exchanger 6 Silencer Part 7 Bypass Path 8 Heat Exchange Case 9 Inlet 10 Outlet 14 Auxiliary Heat Exchanger 15 Neutralizing Tank 16 Communication Port 19 Neutralizing Agent 26 Exhaust Thermistor

Claims (1)

A main heat exchanger that recovers sensible heat from the exhaust gas generated by combustion of the combustion burner and heats the flowing water, and the main heat exchanger and the flowing water heated by recovering latent heat from the exhaust gas after heat exchange with the main heat exchanger Auxiliary heat exchanger to be supplied, a heat exchange case that houses the auxiliary heat exchanger and has an exhaust gas inlet above the bottom and an outlet at the top, and an auxiliary heat exchange that communicates with the bottom of the heat exchange case A neutralization tank filled with a neutralizing agent for neutralizing and draining the strongly acidic drain water generated in the heat exchanger, and the heat exchange case and the main heat exchanger are provided at the bottom of the main heat exchanger. The silencer part and the lower part of the silencer part and the inlet of the heat exchange case communicate with each other through a bypass passage so that the exhaust gas makes a U-turn through the sun lenser part and the bypass passage and flows into the heat exchange case . In the present invention, the bypass passage has an exhaust. By detecting the rise of the scan temperature provided with an exhaust thermistor for detecting the soot clogging of the main heat exchanger, the exhaust thermistor even clogging or leak of the main heat exchanger and the auxiliary heat exchanger of the neutralization tank, leak A latent heat recovery type water heater characterized by detecting a decrease in detected temperature due to dripping of water and stopping the combustion and notifying this.

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